What Your Backup Generator Actually Has to Carry

Nobody argues about backup power during an outage. The argument, if there is one, happens months earlier, and it is not about whether to buy a generator. It is about what the generator has to carry.

That list is the real decision. It sets the size of the equipment, it sets what kind of transfer switch you need, and it sets the price. Two buildings the same size can need very different systems, and the difference is almost never the square footage. It is what is plugged in and what happens to it when the power stops. Get the list right and the rest of the project is straightforward. Get it wrong and you find out during the outage, which is the worst possible time to learn that the freezers were never on it.

A generator does not back up a building, it backs up a list

It is tempting to think of backup power as something that covers the property. It does not. It covers whatever was wired to it, and everything else goes dark exactly as it would have anyway.

So the work starts on paper. Walk the building and sort the equipment into what has to keep running, what can wait a few hours, and what can be off until the grid comes back. Most facility directors find the middle group is larger than they expected, and that is where the budget gets made or lost.

Write the list down rather than carrying it in your head. It becomes the scope your quote gets built against, and it is the document you will want a year later when somebody asks why one circuit is on backup and another one is not.

Some systems cannot take even a short gap

Sorting by importance is not enough on its own, because two systems can be equally important and still need completely different equipment. The question that separates them is simpler: can this load tolerate a break in power at all?

Some can. Lighting in a warehouse aisle can come back thirty seconds later and nothing is lost. Some cannot. PECO works with businesses like cold storage and labs that need uninterrupted power for critical systems, and the backup systems it installs run for medical and laboratory environments, data centers and server rooms, and industrial and manufacturing facilities. For loads like those, the handoff matters as much as the generator.

That is what the transfer switch decides. An automatic transfer switch senses the outage and moves the load over without anyone driving to the site to throw anything. PECO includes automatic transfer switch setup as part of its standard generator installation package in most cases, which means the default answer for a commercial building is usually the automatic one.

The equipment follows the list, not the other way around

Once the list exists, the machine is a consequence of it rather than a starting point. This is the part buyers most often do backwards, picking a size from a competitor's quote or from what the last building had.

PECO evaluates your power needs, recommends the right system, and makes sure it is the right fit for the building. It is an authorized Kohler installer and also works with Generac systems, so the brand follows the requirement instead of the requirement bending to fit one brand.

The same is true of the parts nobody photographs. The power distribution to essential systems and the generator panel wiring are what actually deliver the list you wrote, and equipment testing, startup and support are what prove it works before anyone depends on it.

The project is not finished when the generator is running

A generator that runs is not the same as a generator that is signed off, and the gap between those two states is where problems sit quietly for years.

PECO manages the entire process: choosing the equipment, pulling the permits, the wiring, and the final integration. Every system it installs is code compliant and includes full testing and sign off. Timing depends on the building: commercial projects vary with the size of the job and with permitting, so the schedule is set once the scope is known rather than promised up front.

Start with a walkthrough, not a quote

You cannot price backup power from a phone call, because the list does not exist yet. The first visit is about the building.

PECO installs backup power for commercial, industrial and residential properties across Massachusetts, and works with property managers and facility teams on the buildings they are responsible for. Bring the systems that worry you most and the ones you are unsure about, and the walkthrough will sort them.

Call PECO at (781) 938-6000 to walk your building and scope a backup generator installation.